Broaching machine



Feb. 29, 1944. OAKLEY BROACHING MACHINE Filed July 6, 1942 INVENT OR.

Patented Feb. 29, 1944 BROACHING MACHINE John Oakley, Springfield,Mass., assignor to Perkins Machine and Gear Company, West Springfield,Mass., a corporation of Massachusetts Application July 6, 1942, SerialNo. 449,911

4 Claims.

This invention relates to improvements in breaching apparatus.

The principal objects of the invention are directed to the provision, inbreaching apparatus wherein the breach is reciprocated back and forth,

of means to move the breach away from or out a of the work for andduring the return or nonworking stroke of the breach relative to thework. Particularly the invention relates to breachin apparatus andoperations where high speed and accuracy is desired and necessary.

The invention is especially adapted where a breach tool is reciprocatedrelative to the work being broached and performs the breaching operationas it is pulled rather than pushed. A breaching operation where thebreach tool is pulled through or past the work is preferred to anoperation where the breach is pushed since the operation may beperformed with greater speed and accuracy and with less strain on thework and breach.

sary movement thereof is relatively small in order to clear the workmakes it possible to operate at high speed. I

It has been customary in breaching operations to move the work away fromthe breach for the return stroke of the breach but the mechanismtherefor is necessarily cumbersome and heavy and has had much to do withslowing down breach operations. In applicant's case the breach carrieris readily swingable, it is not excessively heavy and the actuatingparts therefor may be simple in construction and eflicient in operationso as to obtain the desired speed of operation.

With the foregoing and various other novel features and advantages andother objects of my invention as will become more apparent as thedescription proceeds, the invention consists in certain novel featuresof construction and in the combination and arrangement of parts as willbe hereinafter more particularly pointed out in the claims hereuntoannexed and more fully described and referred to-in connection with thaccompanying drawing wherein:

Fig. 1 is a side elevational-view of a breaching apparatus having thenovel features of the invention associated-therewith;

Fig. 2 is a front elevational view of th apparatus shown in Fig. 1;

Figs. 3 and 4 are diagrammatic sectional views showing the breachcarrier and operating means in different relative positions; and

Fig. 5 is a side elevational view of the carrier operating means.

Referring now to the drawing in detail, the novel features of theinvention will be more fully described.

A support is represented by 2 in which a slide 4 is suitably guided forreciprocation. In the drawing, the parts are arranged for reciprocationof the slide in a vertical plane but it may reciprocate in any otherplane as well.

Any suitable means may be employed for reciprocating the slide and beingno part of the present invention the same is not shown. It is desiredthat the slide be pulled rather than pushed during the cutting stroke ofthe breaching tool or tools to be reciprocated by the slide.

A bracket 6 is secured to the lower portion of the slide in which abreach carrier 1 is pivoted at 8 for swinging movements back and forthtowards and away from the slide.

The upper portionof the carrier swings between side-cheeks ID of abracket l2 which is secured to the slide 4 near its upper end. A breachor breach sections represented by B may be clamped to the carrier byclamps [4 or by any suitable means.

As the slide reciprocates in one direction, which inthe embodiment ofthe invention shown is thedownward direction, the teeth act on the work.This movement may be called the working stroke while the stroke in theopposite direction may be called the return stroke.

Broaching apparatus of the general type shown is adapted for variouspurposes but a particular case where it is desired to move the breachaway from the work during the upstroke or return stroke iswhere theteeth are being formed on an internal gear. In such a case the said gearmay be suitably supported in a position and disposed around thebreaching apparatus and rotated in astep by step manner by some suitablemeans in proper timed relation to the operation of the slide so thatsuccessive teeth may be formed.

The above is merely by way of explanation since it is usually desired inbreaching operations to move the work away from the breach for thereturn stroke of the breach.

The upper end of the breach in the presen embodiment of the invention isacted upon in order-to swing the breach towards and away from theWork-and maybe accernplished in other ways, than as shown and described,with equal facility.

A cam shaft 20 is oscillatablein bracket I2 and-it has a flat portion22.- The side at the upper end of the breach carrier 1 is formed to abutand ride on the cam, as shown in Figs. 2

"and '3;

With the cam shaft in the position shown in Fig. 3 the breach carrier isheld outwardly to hold the broach in outer working position during thedownward working stroke of the slide. When the cam shaft is oscillatedcounter clockwise to the position of Fig. 4 the carrier and broach mayswing inwardly so that the broaoh is moved away from the work. Thisoccurs prior to the up or return stroke of the slide.

The carrier is urged to its return stroke position by a compressionspring or springs 24 disposed in a socket 36 of the carrier and at therear of a plate 28 secured to the bracket l2. When the cam shaft isoscillated or rotated to the non-working position of the carrier andbroach, as shown in Fig. 4, the spring or springs urge the carrierclockwise against the said cam shaft 20 to the position of Fig. 4.

Various means may be employed for oscillating the cam shaft 20 but inthe form of the invention shown a lever 38 on the end of the shaft has aprojection 32 on its outer end for engaging with a cam or otheractuating means.

A cam 34 is carried by a bracket 35 secured to the support so that asthe broach approaches the limit of movement in its working stroke theprojection 32 of the lever 30 brings up against the cam 34 so as toswing lever 30 clockwise whereupon the carrier 1 is free to swing sothat spring 24 urges the carrier and broach clockwise. Thereby in theupward or return stroke of the slide the broach teeth pass 'by and areout of contact with the work being broached.

To insure movement of the breach away from the work as when spring 26may become inoperable a stud 40 projects from the carrier 1 and extendsthrough an opening 42 in bracket l2. This stud is so positioned withreference to the cam 34 as to engage the latter which acts thereonsubsequent to the swinging of lever 30 to move the carrier clockwise inthe event spring 24 rails to cause the carrier to follow the movement ofthe cam shaft 22.

In cases where desired means may be provided for acting on the cam shaftwhen the slide reaches the upper limit of its returnstroke so as toinsure the carrier and broach being properly positioned for the downwardworking stroke. To that end a lever 31 similar to lever 33 may beprovided as may be a stud 4| on the side of the bracket opposite to thatshown in Fig. l. A cam similar to the cam 34 may be arranged to act onthe lever and stud after the manner already described, when the slidearrives at the upper end of its stroke.

In operation it will be understood that the slide operating means willbe such as to exert a pulling action thereon so that the broach acts onthe work with a pulling action. By pivoting the carrier as described itis readily swung away from the work and need have but a small amount ofmovement to clear the work. Altogether the invention not only makes highspeed operation possible but the accuracy of work is equal to if notsuperior to that obtained with prior art apparatus.

The novel features ofthe invention are adapted for various broachingoperations where it is desired and necessary to move the broach awayfrom or out of the work for the return or nonbroaching stroke of saidbroach.

The invention may be embodied in other specific forms without departingfrom the essential characteristics thereof. Hence, the presentembodiments are therefore to be considered in all respects merely asbeing illustrative and not as being restrictive, the scope of theinvention being indicated by the appended claims rather than by theforegoing description, and all modifications and variations as fallwithin the meaning and purview and rang of equivalency of the appendedclaims are therefore intended to be embraced therein.

What it is desired to claim and secure by Letters Patent of the UnitedStates is:

1. The combination in broaching apparatus of, a support, a slidereciprocable in opposite directions therein for working and returnstrokes, a carrier for a breach extending longitudinally of the slidepivoted at a certain end thereto for swinging movements between outerWorking and inner non-working positions, said certain end of the carrierbeing the leading end thereof in movements of the slide in workingstrokes, and carrier actuating means for positioning said carrier inworking position during working strokes of the slide and for positioningit in non-working position during return strokes of said slide.

2. The combination in broaching apparatus of, a support, a slidereciprocable vertically therein in a downward Working stroke and anupward return stroke, a carrier for a broach extending along said slidein the direction of its movement pivoted at its lower end for swingingmovements between outer and inner working and nonworking positionswhereby it may be in working and non-working positions during work andreturn strokes of the slides, and actuating means for said carrier toposition the same in working and non-working positions during work andreturn strokes of the slide respectively. p 3. The combinationinbroaching apparatus of, a support, a slide reciprocable verticallytherein in a downward working stroke and an upward return stroke, acarrier for a broach extending along said slide in the direction of itsmovement pivoted at its lower end for swinging movements between outerand inner working and nonworking positions whereby it may be in workingand non-working positions during work and return strokes of the slides,means for releasably holding said carrier in working position during theworking stroke of the slide, and means for releasing said holding meansas the slide moves in its return stroke.

4. The combination in broaching apparatus of, a support, a slidevertically reciprocable therein in downward and upward working andreturn strokes, a carrier for a broach extending along said slide in thedirection of its movement, said carrier being movable relative to saidslide except for a single pivotal connection therewith at its lower endwhereby said movement is confined to swinging in and out relative tosaid slide between outer and inner working and non-working positions ina direction transverse to the direction of movement of the slide,holding means operable relative to said slide for releasably engagingthe carrier remote from said pivotal connection for holding said carrierin working position during the entire working stroke of the slide, meansfor actuating said holding'means for the working stroke of the slide andto release the same for the return stroke thereof, and means for movingsaid carrier to non-working position when released by the holding means.

JOHN OAKLEY.

